As a conventional crimp-style terminal, the one shown in FIG. 1 is known (for example, see Patent Literature 1). This crimp-style terminal 110 includes an electrical connection unit 111 which is electrically connectable with a not shown mating side terminal, a conductor crimp unit 112 which is almost U-shaped in section and crimped and connected to a conductor (a core wire) Wa formed by twisting together a plurality of element wires Wc of an electric wire W, and a coating swage unit 115 which is fixed to an insulating coating part Wb of the electric wire W. Three concave-grooved serrations 118 that extend in a direction orthogonal to a longitudinal direction of the conductor Wa are formed in an inner surface 112a of this conductor crimp unit 112.
Then, when the conductor Wa of the electric wire W is crimped to the conductor crimp unit 112 of the crimp-style terminal 110 by swaging, and the element wire Wc of the conductor Wa is squeezed into the concave-grooved serration 118 while being deformed, an oxide film on a surface of the element wire Wc of the conductor Wa is torn staring from a serration edge 117 which is an edge of the serration 118 to generate a new surface, and close contact is established between the new surface and the conductor crimp unit 112 of the crimp-style terminal 110, by which electrical connection is attained.